This invention is concerned with a manganese-activated zinc orthosilicate phosphor, Zn.sub.2 SiO.sub.4 :Mn. The phosphor emits in the green region of the visible spectrum and is used, for example, in fluorescent lamps and cathode ray tubes.
Some of the problems associated with Zn.sub.2 SiO.sub.4 :Mn phosphors are their relatively poor fluorescent lamp performance and maintenance. Poor maintenance means that the light output, or lumens per watt, of the phosphor decreases to a greater extent during lamp life than is desirable. This invention is concerned with a manganese-activated zinc silicate phosphor having an improved reflectivity resulting in an improved fluorescence efficiency.
The importance of high-performance, green-emitting phosphors with low depreciation characteristics in fluorescent lamps, has increased in recent years with the growing demand for high CRI performance lamps. For that reason, in particular, an improved method for preparing manganese-activated zinc orthosilicate phosphors would represent a significant advancement in the art.